Method of treating multifilament yarn



1966 c. A. FLETCHER ETAL 3,286,321

METHOD OF TREATING MULTIFILAMENT YARN Filed Nov. 22, 1963 6 Sheets-Sheet 1 z 4 5 a a 6 f8 W FIG. 2. 4 4

30 F/G 3 CHARLES A. FLETCHER RICHARD F. DYE)? 3/ INVENTORS' 1966 c. A. FLETCHER ETAL 3,286,321

METHOD OF TREATING MULTIFILAMENT YARN 6 Sheets-Sheet 2 Filed Nov. 22, 1963 FIG. 4.

I I J 1 FIG.

FIG. 7.

CHARLES A. FLETCHER RICHARD F. DYER INVENTOR5 BY QM ArroR/vsrs Nov. 22, 1966 C. A. FLETCHER ETAL METHOD OF TREATING MULTIFILAMENT YARN Filed NOV. 22, 1963 [95 //J V 9s FIG. .9.

[/5 V /J1 AP v FIG. H.

6 Sheets-Sheet 5 .IV/ I CHARLES A. FLETCHER RICHARD I". DYE/i INVENTORS BY @MM AT TORNEYS 1966 c. A. FLETCHER ETAL mnwnoo 0F TREATING MULTIFILAMENT YARN 6 Sheets-Sheet 4.

Filed Nov. 22, 1963 FIG. /7.

FIG. 23.

FIG. /8.

CHARLES A. FLETCHER RICHARD F. DYE/P INVENTORS BY @MM Aime-M 4/. ou/-06? ATTORNE Y5 1966 c. A. FLETCHER ETAL. 3,286,321

METHOD OF TREATING MULTIFILAMENT YARN 6 Sheets-Sheet 6 Filed Nov. 22, 1963 FIG. 22.

c/mmss A. FLETCHER RICHARD F. 075/? INVENTORS B A TTORNE'YS United States Patent Qfiice Patented Nov. 22, 1966 3,286,321 NIETHOD F TREATINgrI MULTIFILAMENT YAR Charles A. Fletcher and Richard F. Dyer, Kingsport,

Tenn., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey H Filed Nov. 22, 1963, Ser. No. 325,719 7 Claims. (Cl. 28-72) This invention relates to a method for the treatment of textile yarns. More particularly, this invention concerns a method wherein a new type jet is supplied with high velocity gas which imparts spaced entanglements to continuous filament synthetic yarns and tows.

This application is a continuation-in-part of our parent application Serial No. 183,448 now US. Patent No. 3,220,082.

For many years. various textile treatment jets utilizing high velocity gas have been used in the textile industry for imparting to yarns a variety of physical properties and appearances. Illustrative of these jets are those shown in US. patents such as 2,067,251, 2,100,588, 2,379,824, 2,460,390, 2,661,588, 2,737,688, 2,884,756, 2,924,868, 2,932,935 and 2,962,794. The several jets which have been described in the prior art have the capability of imparting many different treatments to yarn. However, generally speaking, the prior art jets are best suited for a specific treatment. As new and improved configurations or physical properties for yarns are arrive-d at, treatment jets are needed for use in manufacturing these new products. I

A treatment known for some time in the industry as intermingling, entangling or entwining yarn is now being used to improve the handling of zero twist yarn in various textile operations such as crimping, beaming, sizing, weaving, twisting, knitting and the like where various amounts of twist have heretofore been used and are normally required. Many of the existing jets mentioned above may be used for producing such type yarn, generically referred to as entangled yarn. However, it is believed apparent that the development of a specific simplified jet construction and method for treating yarn in this manner would be of substantial value to the trade. It, therefore, seems apparent that providing new jets and method which fulfill certain special needs of the industry represents a useful result. After extended investigation we have discovered certain relatively simple jet constructions and methods for the utilization thereof which we believe to embody new and unobvious features.

The new jets of this invention are particularly of a construction for the production of the aforementioned entangled yarn and have a number of advantages over any of the previously available jets, such as low volume and low pressure air or other fluid requirements, one piece interchangeable jet inserts, relatively small size, no adjustment, and simplicity of design.

This invention has for one object to provide a method that lends itself for use in the treatment of yarns and tows for purposes of entangling, entwining or intermingling, as mentioned above, of the individual filaments of a running strand thereof. Another object is to provide a method which may be utilized to process the yarn continuously or to secure randomly spaced treatment along the yarn so as to give the yarn handling characteristics similar to that of yarn which has been twisted. A further object is to provide a method for treating yarn so that the yarn is relatively free of any loops or other noticeable discontinuities but has a marked tendency to remain in a coherent bundle of filaments in textile operations. Another object is to provide a process of the type indicated wherein heated gas is employed thereby reducing gas input to the process.

A further object is to provide a process utilizing a plurality of jets in series thereby minimizing the severity of gas action on the yarn being processed. Still another object is to provide a process wherein the yarn is processed in a jet in which the jet insert is of a certain cornposition and finish. Still another object is to provide a method that is capable of stripping excess liquids oif running strands of yarn in operations such as wet spinning, sizing, dyeing, hot liquid drafting and the like so as to facilitate further treatment of winding of the yarn. Another object is to provide a method which may be used for heating yarns with hot gases or other fluids in connection with drafting and relaxing operations. Still a further object is to provide a method having utility as a frictionless yarn guide. A particular object is to provide an internally entangled 'yar'n of a new structure. A further object is to provide new jet constructions for facilitating the carrying out of the aforesaid process. Other objects will appear hereinafter.

In the broader aspects of this invention our new treatment jet has two distinct parts; a jet body, the purpose of which is to receive and distribute the pressurized gas or other fluid (most frequently clean, dry air) and to support the other part which is the jet insert. This jet insert is a special construction for use in treating the yarn by directing onto the yarn a pressurized fluid received from the jet body in the form of high velocity jet streams. It will be observed as the description pro ceeds that we have provided a construction particularly versatile in this respect by virtue of our construction being susceptible of including certain inserts.

For assistance in a further understanding of this in= vention reference will be made to the attached drawings forming a part of this application.

FIGURE 1 is a side elevation view largely in section illustrating our simplified jet.

FIGURE 2 is a semidia-grammatic view of one illustrative process embodiment of textile operation wherein our new simplified jet construction may be used.

FIGURE 3, likewise, is a semidiagrammatic view some what in the nature of a flow sheet of another embodiment of textile operation wherein our new simplified jet construction may be utilized.

FIGURE 4 is still a further s'emidiagrammatic view of process and apparatus arrangement wherein the new simplified jet construction of the present invention may be employed.

FIGURE 5 is .a side elevation view of a modified jet insert such as may be used in our simplified jet of FIGURE 1 so that other functions may be accomplished.

FIGURE 6 is an end elevation of the insert structure of FIGURE 5.

FIGURES 7-15, inclusive, are illustrations similar to FIGURES 5 and 6 of other in's'ert constructions and configurations.

FIGURE 16 is a side sectional view showing another way of mounting the inserts in the jet.

FIGURES 17 and 18 are diagrammatical illustrations on aconsiderably enlarged scale of some of the yarn structures fed and obtained using the various jet construction referred to above for the processing of yarns.

FIGURE 19 is an end sectional view showing a jet assembly featuring a yarn threading slot.

FIGURE 20 is a top sectional View of the same slotted jet assembly.

FIGURE 21 is -a side elevation cross-section of a compound jet arrangement.

FIGURE 22 is a side elevation cross-section of a modified arrangement for the jet of FIGURE 1.

FIGURE 23 is an enlarged longitudinal view of a moderately entangled yarn.

FIGURE 24 is an enlarged longitudinal view of a very highly tightly entangled yarn.

Referring to FIGURE 1 this invention is there shown in one of its simplest forms. The jet body, designated by the numeral 1, is drilled and counter-bored to receive the pressurized gas conduit 2, at the bottom and also drilled through the sides to receive a ceramic jet insert 3, in such a manner that the center portion of the insert is incapsulated in the annulus 4, formed by the extension of the hole previously drilled for the gas conduit. The insert 3 itself is tubular in shape and has two inlets 5, which direct the pressurized gas from the annulus 4, into the treatment chamber 6. The yarn strand to be treated through the treatment chamber 6, as shown by the alternated filament bundle 7.

Although an understanding of the functioning of this simplified jet is apparent to some extent from the foregoing description, a further understanding will be had from a consideration of the following examples:

Example I This example is in accordance with FIGURE 2, concerns the utilization of the jet as applied to a dry spinning process for the production of 55 denier, 13 filament dull entangled acetate continuous filament yarn.

The yarn strand 17, is formed by the extrusion of the acetate dope through a spinnerette jet 18, into a spinning cabinet 19, where the individual filaments are partially cured and combined into a single yarn strand. The yarn then passes out of the cabinet and contacts an oil applicator roll 20, where a yarn lubricant 21, is applied to it. It then passes around a godet roll 22, and into a cellector housing 23, which contains the treatment jet 11, of this invention. Pressurized dry, clean air is supplied to the jet through conduit 12, and the undesirable oil-laden exhaust from the jet is collected and removed by the collector housing and connecting gutter 23, as described in more detail in companion application Serial No. 138,943, now U.S. Patent No. 3,103,731. The yarn passes out of the housing 23, over ceramic guides 24 and 25, and into a conventional traverse mechanism 26, from whence it is wound into a package for use in subsequent textile operations. The conditions in the vicinity of the jet are as follows:

Yarn speed-660 meters/min. Yarn tension at the treatment jet5 grams (0.0909 g./

Jet supplied with 15 p.s.i.g. treatment air The yarn produced has the following physical properties:

55 denier13 filament-0 twist Average entanglement spacing4 inches 2.3 percent by weight lubricant 25 percent elongation 1.2 grams/denier (dry) strength Example 11 Another example of the use of the invention is illustrated in FIGURE 3, as applied to the drafting and entangling of a multifilament, continuous filament polyester fiber. The yarn strand 30, is withdrawn from an unoriented supply package 31, and passes through a tension gate 34. It passes over a ceramic guide 35, and onto a drafting input and advancing roll set 36. A hot pin 37, heats the yarn; and it is oriented or drafted by the drafting output and advancing roll set 38. It then passes through the treatment jet 32, supplied with pressurized air through conduit 33, from a source not shown, and is wound into a yarn package 39, by a conventional winding device. The treatment jet in this example imparts to the yarn at random intervals an entwining or intermingling of the individual filament around each other.

The resulting yarn strand is bound together by these entwined spots and, in subsequent textile operations, handles in the same manner as yarn that has been twisted. The conditions in the vicinity of the treatment jet are as follows:

Yarn speed-422 yds./min. Yarn tension-9 grams (0.128 g./d.) Jet supplied with 20 p.s.i.g. dry air The yarn produced had the following properties:

70 denier-33 filament Average spacing between entanglements2" Example III A third example of the utilization of this new and simplified jet is illustrated in FIGURE 4, as applied to the production of a 2700 denier, 200 filament textured filament, modified acrylic yarn, such as described in greater detail in companion Haynes U.S. Patent No. 3,099,064. The yarn strands 40, from the supply packages 41, of previuosly oriented fiber pass through a set of feed rolls 42, into a set of treatment jets 43, supplied with pressurized air from a source not shown where fibers are individually entangled. They are then combined into a tow 44, by passing between guide pins 45, and crimped in a crimping machine 46. The crimped tow 47, is then heat set and relaxed under zero tension in an oven 48, and separated into individual ends 49, again for winding on a conventional winding device 50. The entanglement in this process is used in the place of twist to maintain the integrity of the individual strands while they are being processed in tow form so that, upon completion of the heat setting, they can be split apart and wound on individual package. The texture of the yarn is derived from the crimping and not the entangling. The operating conditions-in the vicinity of the treatment jet are as follows:

3 percent overfeed between feed roll and crimper Yarn speedl75 meters/minute Air pressure supplied to treatment jet40 p.s.i.g.

The yarn produced is characterized by interfilament entanglements at /z to 1" intervals and a crimped texture which imparts to it a unique appearance and hand, particularly suitable for use in carpets, upholstery fabrics, and other textile products.

The jet constructions used in the above examples consist of ceramic tubes in a pressurized annulus, as illustrated in FIGURE 1. The preferred design of the insert and its relationship with the annulus can be further described by defining certain ratios and parameters between the various dimensions and the yarns to be treated. Referring to FIGURE 1, the yarn passage diameter 6, preferably is 5 to 20 times the yarn diameter. The length of the yarn passage 6, preferably is 3 to 15 times its diameter. The diameter of the air passage 5, preferably is 1 to /2 times the diameter of the yarn passage 6. The length of the air passage 5, preferably is 4 to 10 times its diameter. The interior edges at the ends of the yarn passage 6, are chamfered or rounded so as to eliminate possible yarn damage and increase running efficiency. The diameter of the insert is selected so as to allow suflicient and proper air supply to the air passages 5.

The process of this invention thus is felt to constitute an improvement over the process as disclosed in companion, co-pending Dyer application S.N. 75,396 in that the volume of air required for attaining an equal amount of filament interweaving is substantially less.

Example IV A comparison was made of an orifice plate/venturi jet as described in U.S. Patent 2,924,868 and Serial No. 75,396 with a semi-taper jet such as shown in FIGURE 7. The yarn passage 76 in the semi-taper jet was 0.101" in diameter with a 4.3 expanding taper 72 on the outlet side. The air hole entrances 73 were straight and of a 0.080" diameter. Both jets were run on 150/ 38/0 bright acetate yarn at similar conditions of yarn speed and tension.

The orifice/venturi jet of the prior art required 22 p.s.i.g. air pressure and an air usage of 6.25 c.f.m. of free air at standard conditions to obtain entanglements of 3 to 6" spacing. The jet of FIGURE 7 of this invention required only 6 p.s.i.g. air pressure and two cubic feet per minute of free air at standard conditions to produce the same degree of entanglement.

Although in the above description one type of insert for the jet has been described; there are several variations which can be applied to the insert so as to achieve different effects. It is advantageous to use a jet body equipped with interchangeable inserts especially suited for imparting a desired treatment to yarns of different chemical and molecular structure. These yarns may better use different inserts because of their varied physical properties and handling characteristics.

It has been found that the material used for the inserts 3 has a substantial effect on the process. This appears to be related to the type of surface finish treatment chamber 6 as well as possibly the electrical conductivity of the insert material and its place on the triboelectric scale relative to the position of the synthetic filaments being processed. The following example illustrates this.

Example V Average Entanglement Spacing Inches Insert Material (Approximately 8 R.M.S. Finish) Aluminum Brass Steel Oxide Teflon Ceramic Air Pressure to Jet:

5p.s.i.g 4.9 7.0 6.5 30.0 7% p.s. 2. 2 2.1 2. s 10. 0 10 p.s.ig 1.5 1.2 2.7 5.0

Process Air Single .Tet Fig. 1

Brass Insert, R.M.S. Micro Inch Surface Finishes, Average Entanglement Spacing 32 R.M.S. 16 R.M.S. 8 R.M.S. 14 R.M.S.

Air Pressure to Jet:

7% p.s.i.g 1. 5

The R.M.S. referred to above may be measured by 9. Brush surface finish analyzer or may be measured by .v'isual comparison. Such visual comparison may be made with a set of surface finish standard samples such as those made by the University Machine Company of Cambridge, Massachusetts.

7 In the foregoing table, it can be seen that inserts made from metallic materials such as brass and steel tend to produce somewhat closer entanglement in the yarn than a ceramic or plastic insert. It is also indicated that the surface finish in the yarn treatment chamber 6 has a major effect on the frequency or spacing of the entanglements. A highly polished .25 R.M.S. mirror-like finish in the chamber 6 produces much closer spaced entanglements than an 8 R.M.S. micro inch finish for a given insert material, size and air pressure.

In some cases, it has been found to be desirable to treat the yarn a plurality of times to increase the frequency of entanglement without increasing the severity of the effect of the gas on the yarn. It has been found that under certain circumstances very high air pressures, when used in small inserts, cause excessive broken filam'ents. This combination of high air pressure and small inserts may also cause excessively tight interweaving of the filaments at random spots along the yarn, causing a change in yarn appearance at these spots which show up as flashes or short streaks as shown in FIGURE 24 when the yarn is woven into fabric. The following example illustrates the substantial reduction in air pressure required to produce a given level of entanglements when the yarn is treated a plurality of times in a series of inserts as compared to a single treatment in a single insert.

Example VI Example VI of this invention is illustrated in FIGURE 21 as applied to a dry spinning process for the production of denier, 38 filament, bright, entangled acetate continuous filament yarn. In this embodiment, a series of jet assemblies 213, is used to treat the yarn strand 215. The jets are contained in a single housing 212, for the purpose of collecting lubricant blow-off which is then carried away by the exhaust system 214. Process air is supplied from the plenum chamber 211, on top of the collector housing.

The table below describes the operating conditions and resultant fabric appearance of yarn from this apparatus. Yarn speed-720 meters/minute Take-up tension'15 grams Multiple Jet Fig. 21

Pressure to Jet p.s.i.g. Avg. Entangle- Avg. Entanglement Space, Appearance ment Space, Appearance Inches Insurance 21 Between Figs. 17 and 23.

8 Do. 4 Close to Fig. 23.- 7 Close to Fig. 23. 1. 5 Fig.- 23.

1. 2 Between Figs. 23 and 24. 4. 5 Fig. 23 3. 7 Fig 23 3.0

Between Figs. 23 and 24;

Example VII Another convenient form that the jet design may take is to build the jet into the air header directly. This is illustrated in FIGURE 22 as applied to a dry spinning process for the production of 150 denier, 38 filament, dull, entangled, continuous filament acetate yarn. In this configuration the jet assembly is designed in the shape of a threaded plug 226, which screws into a lubricant blowoif collector and exhaust pipe 227. Air is supplied through the bottom 228, by conventional means. The yarn strand to be treated is designated by the numeral 229.

The following table describes the operating conditions and entanglement produced from this apparatus. The insert had a 0.101" diameter yarn passage and 0.081" diameter air entrance holes.

Yarn speed--660 meters/minute 2 Between Figs. 17 and 23. 8 Close to Figure 23.

5 FigureS 23.

0. Between Figs. 23 and 24. Close to Figure 24. Figure 24.

The advantages of this apparatus are simplicity of design, compactness and low cost of fabrication. The pipe is positioned parallel to the spinning machine and jets are located in it as needed to treat the ends of yarn as they pass to the yarn take-up machines.

' While the insert illustrated in FIGURE 1 has two air passages of a cylindrical configuration, other shapes and arrangements of air passages along the yarn passage are desirable for imparting different treatments to various kinds and sizes of yarns. For example, the treatment jet used in the third process example, FIGURE 4, may have as its insert the design illustrated in FIGURE 5. This figure illustrates an insert with four air passages 5, of cylindrical configuration whose axis intersect the axis of a cylindrical y-arn passage 6, and are perpendicular to each other. FIGURE 6 is an end elevation view of the same insert. FIGURE 7, a sectional side elevation view, illustrates an insert with a conical configuration 72, on one end of cylindrical yarn passage 76, and conically shaped air passages 73. In this jet the included angle of the tapered portion 72, has been found to be most effective when it has a value of 4 to 15, with 7 being a preferred value. The diverging portion of the jet forms the yarn exit from the tube 76, and promotes self-threading of the jet. This self-threading feature makes this jet particularly useful as a frictionless thread guide for use in a beaming operation where the yarn strands must be supported and guided over several 100 ft. at times. For this use the diameter of the cylindrical part of the passageway 76, should be as small as possible to reduce air usage re quirements and may be from 2 to 10 times the yarn diameter. With low air pressures of 0.1 to 5.0 psi. gauge, the yarn bundle is supported on a film of gas throughout the passageway 76, as a minor portion of the gas escapes through the yarn entrance, and a major portion escapes through the yarn exit taper 72. This division of the gas exhaust gives a gentle forwarding action to the yarn which helps to overcome atmospheric air drag when the yarn is traveling at high speeds or tension from the centrifugal forces generated as the yarn balloons out in the course of removal from the end of a supply package. The small size of the yarn passage permits the use of a minimum of air and thus avoids any derangement of the yarn filaments by the jet air guide which would cause them to take on an entwined, entangled, or loopy appearance. Of course, if desired, higher air pressures of say 5 to p.s.i. may be used to cause any desired degree of entanglement or looping of the yarn filaments as well as the aforementioned yarn guiding effect.

The process and jets of this invention also have a wide range of adaptability in producing different types of products. This is illustrated in the following example.

Example VIII The semi-taper jet of FIGURE 7 was set up as shown in FIGURE 2 on a yarn spinning machine. The conditions of operation were varied to produce three distinctly different appearing yarn products as judged by the appearance of the yarn in fabric.

220 denier, 50 filaments cellulose acetate yarn pigmented a blue color and spun at 714 m./m. was used in each test.

In the first test, the jet was operated at a pressure of 7.5 p.s.i.g. and the winding tension of the yarn was 15 grams. Under these conditions the filaments of the yarn had a gentle type interweaving with an entanglement spacing of two inches when examined carefully under a microscope. Its appearance was substantially like that of FIGURE 23. When woven into fabric as filling, no difference in appearance could be detected between it and untreated yarn; yet there was no need to twist the treated yarn to make it weave acceptably while 1.0 t.p.i. of twist was required in the untreated yarn to avoid excessive broken filament damage and fuzziness in the fabric.

In the sec-0nd test, the jet was operated at 30 p.s.i.g. air pressure and the yarn tension was raised to 20 to 25 grams. This caused the interweaving of the filaments to become much more severe and acute. It caused a marked change in the luster of the yarn at the points of very tight entanglement 103 and 104. The yarn appeared somewhat as in FIGURE 24 with some flaring of the filaments between the entangled spots and with the spots of entanglement being about A3 to A. long and spaced about /2 :to 1" apart. When woven as filling into fabric, the spots of tight entanglement showed up as short flashes or streaks and tended to simulate the general effect of a skip dent type weave. By transmitted light, the fabric appeared to contain a thick and thin type yarn with randomly occurring short lengths of thin yarn appearing throughout the fabric.

In the third test, the jet was operated at 66 p.s.i.g. air pressure and the winding tension was reduced to 12 grams. In this case, the yarn took on an over-all delustered and fuzzy effect. The yarn appearance was loopy with spots of extremely tight filament interweaving alternating with randomly occurring arch shaped loops as shown in FIGURE 18. When woven as filling in a fabric, the fabric had the appearance of containing a staple yarn of poor uniformity plus some of the skip dent effect noted in the second test. The surface of the fabric was not as slick and lustrous as that of tests 1 and 2 and somewhat resembled a wild silk yarn fabric. Some of this yarn was also knit into a sock fabric in comparison with an untreated yarn sample having 1 t.p.i. of twist. The treated yarn imparted more thickness to the knit sock and gave it a softer hand than the untreated yarn. The specific volume of the treated yarn was 42 cubic inches/ pound as compared to 33 cubic inches/pound for the untreated yarn.

From the foregoing, it can be seen that the jets and process of this invention have a wide versatility for the treatment of continuous filament yarn to (1) interweave the filaments to substitute for twist without changing the appearance of the yarn; (2) to interweave the filaments tightly at spaced intervals to cause luster variations and novel effects in fabrics and; (3) to tightly interweave the filaments at closely spaced intervals and form long arch shaped filament loops between the spots of entanglement to impart a softer, less slick hand to the yarn and to slightly increase its bulk. The spots of tight entanglement serve to securely lock and arch shaped filament loops in place in the yarn without need for twist or chemical filament binders or adhesives.

The air entrance passages as 5, may be either straight as shown in FIGURE 1 or converging as shown in FIG- URE 7. The converging type air entrance is helpful in accelerating the treatment gas to a high velocity to enhance the entangling or looping and entangling of the yarn filaments when these effects maybe desired. An included entrance angle of 20 to 90 in the air entrance passages allows the use of lower gas pressures for a given level of filament entanglement or loopiness due to the increased kinetic energy imparted to the gas stream by accelerating it to a higher velocity by means of the convering air passages 5.

In FIGURE 8 is shown an enlarged portion of a preferred gas entrance 83, to a jet of the class described. This type entrance to the yarn tube has very low losses due to gas friction and turbulence and in certain instances it may be possible to treat several thousand ends of yarn at substantial savings in cost even though the initial cost of fabrication of the jet may be increased as compared to the straight gas tube 5, of FIGURE 1. In this case a diameter for the yarn passage is selected depending on the yarn denier and the type of treatment desired. In the case shown a value of d is selected for the inside diameter of the yarn passage. The outside diameter of the insert tube is then assigned the value of 1.6d, giving the tube a wall thickness of 3d. The diameter of the gas inlet is .50d, and the entrance to the gas inlet tube is assigned two radii which merge into a straight cylindrical passage. The first entrance radius is given a value of .1001, the center point of this radius being located .1001 from the outer tube surface and .37d from the axis of the gas entrance. This first radius is merged with a second radius having a value of .1511, the center of which is located .lSd from the outer surface of the tube and .5011 from the axis of the gas passageway. All these dimensions are based on a longitudinal cross-section as shown in FIGURE 8. It will be recognized that these values will be slightly dif- 'ferent in other vertical cross-sectional planes that do not pass through the yarn passage axis due to the cylindrical shape of the outer surface of the jet insert.

FIGURE 9, a sectional side elevation View, illustrates a rectangular yarn passage 96, and cylindrical air passages 95. The rectangular yarn passage promotes eddy currents and air turbulence and is useful for increasing the entangling forces on the yarn filaments. FIGURE 10 is an end elevation view of the same insert.

FIGURE 11, a sectional side elevation view, illustrates an insert with three alternately spaced cylindrdical air passages along a cylindrical yarn passage 6. FIGURE 12, a sectional side elevation view, illustrates an insert with one cylindrical air inlet intersecting a cylindrical yarn passage 6. FIGURE 13, a side elevation view, illustrates an insert with cylindrical air passages which intersect the cylindrical yarn passage tangentially. FIGURE 14 is a sectional end elevation view of this same insert. This form of jet is useful when it is desired to impart a false twist to the yarn either for the purpose of improving the compactness and ease of handling of the yarn in an immediately prior or subsequent process step or for the purpose of achieving a curly crimp in the yarn filaments.

While the outer wall of the gas entrances is depicted in FIGURE 14 as tangential with the wall of the yarn passage, it will be recognized that the axial offset of the gas passage 5, from the axis of the yarn passage 6, may be greater or less, depending on the amount of torsional force it is desired to impose on the yarn bundle. If only a low degree of false twist, say a faw turns per inch, is desired in a frictionless thread guide such as shown in FIGURE 7, then the axis of the gas entrance tubes 5, may be displaced only a few thousandths of on inch from the axis of the yarn passageway 6. Such a jet configuration is particularly advantageous in handling delicate yarns to avoid damaging friction over guides and preventing excessive filament separation or entanglement by means of the low level of false twist imparted. Conversely with larger axial offsets and high air pressures, a high degree of filament entaglement or entanglement and loopiness together with a moderate level of false twist may be imparted to a yarn if so desired.

FIGURE 15, is a side elevation sectional view, illustrates a V-shaped yarn passage 106, with an included angle from 170 to and cylindrical air passages 5. Such a configuration is helpful when the jet is located at a point where a change in direction of the yarn path is desired, but space or other limitations require that the yarn must be entangled or looped simultaneonusly with the change in yarn path.

FIGURES 19 and 20 illustrate a jet assembly which features a yarn threading slot for improved operating efficiency and convenience. The slotted jet allows a running strand of yarn to be introduced into the treatment chamber simply by sliding the filaments through the slot. In continuous processes normally associated with the extrusion of synthetic fibers by melt, dry, or wet spinning this feature is highly desirable because the running strand of yarn does not have to be broken in order to thread it through the jet.

The jet consists of an upper body 60, a lower body 61, a spacer 62, a slotted ceramic insert 63, a pressurized gas conduit 64, and a conventional threaded fastener 65. The slot is designated by the numeral 66.

The width of the slot 66, is dependent upon the thickness of the spacer 62, and can be varied to accommodate large or small filament cross-sections. For yarns with filament diameters in the range of .0005 to .002" a .004" spacer is preferred; larger filaments require a thicker spacer. The slot entrance has been provided with radii 67, to facilitate sliding the yarn into the treatment chamber.

A gentle flow of air issues through the fine slot in the insert thus insuring that the yarn filaments are not blown out of the treatment chamber by the more turbulent conditions existing therein. If desired the insert can be rotated with respect to the jet body after threading, misaligning the slots thus providing an additional means of preventing the escape of any filaments from the treatment chamber. The flanges 68, on either end of the insert serve to position the insert in the jet body and to prevent the snagging of filaments in the cracks formed by the junction of the outer diameter of the insert and the inner diameters of the jet bodies.

The jet of FIGURE 15, when used solely as a yarn guide, has particular advantages over the prior art snubbing guides which rub and abrade the yarn rather than floating it on a film of gas. These variations on the design of the insert are not all inclusive but serve to illustrate some of the possible insert configurations within the spirit of this invention. The inserts illustrated in FIGURES 1 and 19 are preferred for producing moderately tight entanglement on yarns from 35 to 500 denier, for example, in acetate spinning operations similar to the one illustrated in FIGURE 2; whereas, the inserts of FIGURE 5 and FIGURE 11 are better suited for producing heavy entanglement on larger deniers in processes similar to the bulking of modified acrylic yarns as illustrated in FIGURE 4. When only a mild entanglement is desired, the insert of FIGURE 12 is preferred. If it is desired to have the insert exert a slight pull on the yarn to facilitate withdrawal or threading or to act as a frictionless yarn guide, a jet similar to FIGURE 7 is preferred. If it is desired to eliminate any slight twisting or swirling of the yarn strand, then an insert similar to FIGURES 9-10 is preferred. The inserts of FIG- URES 7 or 8 are best suited for imparting a bulk or texture to the yarn so as to give it the appearance and hand of staple yarn. If a false twisting effect is desired,

11 the insert of FIGURES 13-14 with tangential air passages is preferred. If it is desirable to dire-ct the exhaust from the jet downward or upward, an insert similar to FIGURE 15 can be used.

All of these inserts exhibit a tendency to remove excess liquids from running strands of yarn; however, the inserts of FIGURES 1, 5, 7, 9, ll, 15 and 19 are preferred for this use. Inserts similar to the ones illustrated in FIGURES l, 7, 9 and 19 are preferred when it is desired to obtain novelty delustered effect on bright or semibright yarns. The configurations of the air passages illustrated are typical of those that can be used; however, certain other shapes would still be within the spirit of this invention. The cylindrical air passages of FIG- URES 1, 5, 9, 11, 12, 13, 15 and 19 are the easiest to form and give very good results, but special effects and higher efliciencies can be realized in using the conical, converging nozzle or other similar configurations of FIGURES 7 and 8.

Reference is now made briefly to FIGURE 16. To achieve a versatile apparatus, one method of mounting the insert in the jet body is accomplished by utilizing O-ring seals 29, and a retaining ring 28, as illustrated in FIGURE 16. For applications where a permanent joint is desired, the two parts are joined by cement 8, as illustrated in FIGURE 1.

While it is not desired to be bound by theory, a further understanding perhaps may be had from the following explanation:

This invention it is thought may be considered an improvement over existing theory long known to those skilled in the art of treating yarn strands with high velocity gases or liquids. Simply stated, the jet streams of high velocity gas impinge on the yarn perpendicularly or at a slight angle to its axis and cause the individual filaments to be separated from each other and rearranged in an entwined, intermingled fashion as they exit from the treatment zone. This is further apparent by referring to FIGURE 17, where a short length of zero twist yarn is depicted with its filaments arranged in a parallel manner and comparing it to FIGURE 18, which depicts two entangled spots 103 and 104, in a short length of yarn treated with an insert similar to that of FIGURE 1. It can be seen that, in bright or semi-bright yarns, entangled spots along the strands of otherwise zero twist yarns have different reflective properties as described in companion Dyer Application Serial No. 145,877, now US. Patent No. 3,103,098. This results in a novel effect when these yarns are woven and finished into fabrics of various constructions. When jets of this invention are used to strip excess liquids off running strands of yarn, the action of the high velocity jet streams on the yarn in the treatment area penetrates through the yarn strand, atomizes any excess liquids present, and expels them as aerosol from either end of the jet insert. This can be further enhanced by utilizing hot or warm gas to vaporize some of the excess liquid.

The use of a heated gas is often desirable in the entanglement process. It is though that this may be so because most man-made fibers are thermoplastic and have a reduced strength at elevated temperatures. This means that as the temperature of the treating gas is raised, the filaments are warmed and become less stiff. The filaments thus become easier to bend and flex so that they interweave with each other more readily. Thus lower gas pressures can be used to obtain a given degree of entanglement of the filaments in a yarn when warm to hot air is used. The temperature need not be as high as the second order transition temperature; however, to give good results.

Example IX This example illustrates the effect of treating cellulose acetate 150 denier, 38 filament bright yarn at a yarn speed of 714 MM while it was being wound at 8.5 grams 12 tension. The apparatus setup was like that of FIGURES 1 and 2 except that the air supply line was provided with a means for heating the air. An insert having a 0.101" diameter yarn passage 6 and 0.081" diameter air entrance holes 5 was used.

Average Entanglement in Inches Air Pressure Air Temperatures in C.

In p.s.i.g.

25 0. Air 50 0. Air 0. Air 0. Air

It can be seen that with 50 to 130 C. air the same entanglement was obtained with 3 p.s.i.g. air as was obtained with 25 C. air but at 6 p.s.i.g., a 50% reduction in air pressure. Or that only 6 p.s.i.g. air at 100 C. was required to give 1.6" entanglement spacing instead of more than 9 p.s.i.g. of 25 C. air.

The heating of yarns, particularly the polyester and polyolefin types, in drafting and relaxing processes can be readily accomplished using this type of jet due to the ex tremely eflicient heat transfer obtained when the hot jet streams separate and encapsulate each individual filament.

The jets of this invention can be designed and operated so' that the yarn appearance and filament arrangement before and after passage through the jet remains the same, or the appearnce remains the same but the filament arrangement is changed, or both the appearance and filament arrangement is changed as may be seen from the foregoing. The treatment jet of this invention is a relatively simple apparatus featuring only two parts, neither of which requires adjustment. It is highly versatile in that any number of different inserts can be used in the same jet body to impart many different treatments to various running strands of yarn. It can be fabricated from ceramic materials, thus eliminating wear caused'by erosion due to the air flow or yarn abrasion and insuring a uniform quality of treatment over long periods of time. It is small in size and can be easily applied to existing textile operations where other type jets will not fit. It can also be adapted for slot threading thus improving operating efficiency and convenience. In summary, this unique jet, featuring small interchangeable ceramic inserts, can be used in the textile industry to entangle, loft, bulk, heat, deluster, texture, false twist and remove excess liquids from running strands of yarn.

Although the invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, variations and modifications can be effected within the spirit and scope of the invention as described hereinabove, and as defined in the appended claims.

We claim:

1. In a process of producing a jet-treated multifilament yarn by blowing said multifilament yarn in a jet with a fluid to obtain an internally entangled yarn product having improved and predetermined entanglement spacing, said process being further characterized in that the amount of fluid required to operate the process is lower than that required with comparable prior processes, the improvement features which comprise preparing the multifilament yarn for processing in the jet, supplying yarn lubricant to this yarn, passing said lubricated yarn through said jet in a manner that the multifilaments may impinge on the inner surface of the jet portion enclosing the yarn undergoing processing, introducing the fiuid into the jet in a direction non-parallel to the direction of yarn movement through the jet but wherein the yarn moves in a direction for at least a part of the time which may be substantially parallel to fluid flow in the jet, the jet being particularly characterized in that the inner surface of the jet which encloses the yarn undergoing the aforesaid processing has a mirror-like surface with a surface roughness value of less than 8 R.M.S., controlling the pressure and tension on the 'multifilaments undergoing processing with fluid in said jet within conventional pressure and tension ranges known to cause the filaments to separate and entangle with other filaments at spaced Zones whereby the aforesaid improved product yarn with predetermined internal entanglement spacing is obtained with said lower amount of fluid supplied to the jet.

2. The process of claim 1 wherein the amount of lubricant applied to the multifilament yarn before processing in the jet is of such amount that some of said lubricant is blown off the yarn during the treatment in the jet.

3. The process of claim 1 wherein the lubricant applied is in excess of 2.3% and the processing in the jet reduces the lubricant content to not more than 2.3%.

4. The process of claim 1 wherein the interior jet surface is mirror-like and non-metallic.

5. The process of claim 1 wherein the interior jet surface is mirror-like and essentially comprised of a polymeric material.

6. The process of claim 1 wherein the fluid used in the process is a heated fluid.

7. The process of claim 1 wherein the fluid is primarily comprised of clean air.

References Cited by the Examiner UNITED STATES PATENTS 2,982,000 5/ 1961 Gonsalves 57-34 2,985,995 5/1961 Bunting et al 5734 2,997,771 8/1961 Martyn 28--1 3,026,597 3/1962 Swaney 5734 3,069,836 12/ 1962 Dahlstrom et a1, 2872 3,079,745 3/ 1963 Breen et .al 2872 3,083,523 4/1963 Dahlstrom et al 5734 3,093,878 6/1963 Fieldman 28--1 3,110,151 11/1963 Bunting et al 57-157 3,116,589 1/1964 Edwards et al 57157 MERVIN STEIN, Primary Examiner.

DONALD W. PARKER, J. KEE CHI,

Assistant Examiners. 

1. IN A PROCESS OF PRODUCING A JET-TREATED MULTIFILAMENT YARN BY BLOWING SAID MULTIFILAMENT YARN IN A JET WITH A FLUID TO OBTAIN AN INTERNALLY ENTANGLED YARN PRODUCT HAVING IMPROVED AND PREDETERMINED ENTANGLEMENT SPACING, SAID PROCESS BEING FURTHER CHARACTERIZED IN THAT THE AMOUNT OF FLUID REQUIRED TO OPERATE THE PROCESS IS LOWER THAN THAT REQUIRED WITH COMPARABLE PRIOR PROCESSES, THE IMPROVEMENT FEATURES WHICH COMPRISE PREPARING THE MULTIFILAMENT YARN FOR PROCESSING IN THE JET, SUPPLYING YARN LUBRICANT TO THIS YARN, PASSING SAID LUBRICATED YARN THROUGH SAID JET IN A MANNER THAT THE MULTIFILAMENTS MAY IMPINGE ON THE INNER SURFACE OF THE JET PORTION ENCLOSING THE YARN UNDERGOING PROCESSING, INTRODUCING THE FLUID INTO THE JET IN A DIRECTION NON-PARALLEL TO THE DIRECTION OF YARN MOVEMENT TRHOUGH THE JET BUT WHREREIN THE YARN MOVES IN A DIRECTION FOR AT LEAST A PART OF THE TIME WHICH MAY BE SUBSTANTIALLY PARALLEL TO FLUID FLOW IN THE JET, THE JET BEING PARTICULARLY CHARACTERIED IN THAT THE INNER SURFACE OF THE JET WHICH ENCLOSES THE YARN UNDERGOING THE AFORESAID PROCESSING HAS A MINOR-LIKE SURFACE WITH A SURFACE ROUGHNESS VALUE OF LESS THAN 8 R.M.S., CONTROLLING THE PRESSURE AND TENSION ON THE MULTIFILAMENTS UNDERGOING PROCESSING WITH FLUID IN SAID JET WITHIN CONVENTIONAL PRESSURE AND TENSION RANGES KNOWN TO CAUSE THE FILAMENTS TO SEPARATE AND ENTANGLE WITH OTHER FILAMENTS AT SPACED ZONES WHEREBY THE AFORESAID IMPROVED PRODUCT YARN WITH PREDETERMINED INTERNAL ENTANGLEMENT SPACING IS OBTAINED WITH SAID LOWER AMOUNT OF FLUID SUPPLIED TO THE JET. 